Papers ox Chemistet and Physics: 



Preparations of the Metals of the Rare Earth Group: H. C. 



Kreraers, University of Illinois 223 



Concentration of Radium from Carnotite Ores: B. S. Hopkins 



and G. C. Ruhle, University of Illinois 227 



Effect of X-Rays on the Resistance of Tin Foil: W. H. Sanders 



and C. J. Lapp, University of Illinois 231 



Industrial Chemical Research: John S. Hessler, Knox College 234 



Research Work as a Preparation for Teaching High School 

 Science: Fred D. Barber, Illinois State Normal Univer- 

 sity, Normal 238 



Content of the High School Course in Chemistry: J. P. Mag- 



nusson, Augustana College 248 



Melting Point, Latent Heat of Fusion and Solubility of Or- 

 ganic Compounds: P. S. Mortimer, Illinois Wesleyan Uni- 

 versity •. , . 251 



The Effect of Alkali Vapors and other Gases at Various Press- 

 ures in Thermionic Detectors: Hugh A. Brown and Chas. 

 T. Knipp, University of Illinois 267 



The Infra-Red Absorption of some Oxides of Nitrogen: B. J. 



Spence, Northwestern University 279 



The Action of Light upon Arsenic Trisulfide Hydrosole: Ray 



Murphy, Illinois Wesleyan University 281 



The Determination of "g": A. C. Longden, Knox College 289 



A Method of Magnifying Small Angular Displacements: Ralph 



C. Hartsough, Illinois Wesleyan University 294 



The Vapor Pressure and Heat of Vaporization of Non-Asso- 

 ciated Liquids: P. S. Mortimer, Illinois Wesleyan Uni- 

 versity 297 



Sound Proofing in Buildings: F. R. Watson, University of 



Illinois 307 



A Simple Device for the Analysis of Sound Waves: C. J. Lapp, 



University of Illinois 312 



A 3000-Volt Lead Plate Shop-made Storage Battery, — Its Con- 

 struction and Charging Characteristics: C. T. Knipp and 

 R. J. Ruedy, University of Illinois 315 



Demonstration of the Wind in the Corona Discharge: Jakob 



Kunz, University of Illinois '. 320 



The Adsorption of Hydrogen Ions by Charcoal: I. J. Jenks, 



State Teachers College, DeKalb 323 



A Method of Determination of Dielectric Constants: A. P. Car- 

 man and G. T. Lorance, University of Illinois 330 



The Effect of Short Electromagnetic Waves on a Beam of 



Cathode Rays: C. J. Lapp, University of Illinois 331 



Effect of Lunar Gravity upon a Quartz Thread Balance: R. C. 



Hartsough, Illinois Wesleyan University 340 



Illinois Coal as a Source of Smokeless Fuel: S. W. Parr, Uni- 

 versity of Illinois 342 



Papers ox Geology axd GEOfiRAPHY: 



The teaching of Geography in the High School: V. I. Brown, 



Watseka Community High School 361 



A Few Criticisms of the Illinois State Course of Study in 

 Geography: C. E. Cooper, Illinois State Normal Univer- 

 sity, Normal 365 



The Hennepin Canal: Robert G. Buzzard, State Teachers Col- 

 lege, DeKalb 371 



Some Contrasts in the Geography of the Virginia Piedmont 

 and the Illinois Plain: Bessie Ashton, University of Illi- 

 nois 378 



Coal Resources of Southern Illinois Counties just North of 



the Ozark Outlier: W. G. Lathrop, Johnston City 383 



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